Slim Whitman, the country singer-guitarist whose high-pitched yodels helped him sell millions of records through ubiquitous TV ads, died on Wednesday (June 19). He was 90.

Whitman launched his career in 1948, when future Elvis Presley manager Tom Parker helped him secure a record deal with RCA Victor. He scored several hits in the’50s, ‘60s, and ‘70s – “Indian Love Call,” “Rose Marie” and “Something to Remember” being among the most notable. Paul McCartney famously credited Whitman with triggering the idea to flip his guitar and play left-handed, after he saw a poster advertising a performance by the country star.

In 1979, Whitman embraced the then-new concept of selling albums via mail-order TV ads. His first mail-order album, All My Best, sold more than 1.5 million copies. Whitman released his last album, Twilight on the Trail, in 2010. McCartney, George Harrison and Michael Jackson were among the many artists who cited him as a favorite.